Project Summary Debates about the potential of public pre-kindergarten (pre-k) programs to close poverty-related early education and health gaps occupy center-stage for scientists, policymakers, and education and public health officials. While there is substantial evidence to support the power of pre-k to promote positive development in the short-term, the mechanisms that explain those positive short-term effects are poorly understood. Moreover, there is no evidence examining pathways for sustaining positive short-term effects into early primary schooling (1st ? 4th grade) to guide actionable decisions to improve education and health for vulnerable young children. We focus on children?s self-regulatory skills (e.g., attention and impulse control; management of emotions; memory, planning, and organization) and the public pre-k classroom features that support their development as prime candidates for mechanisms linking pre-k with education and health outcomes for three reasons: (1) the brain regions underlying developing self-regulatory skills are compromised among children who have experienced significant economic adversity; (2) self-regulatory skills have been empirically documented to underlie education and health outcomes; and (3) self-regulatory skills are sensitive to intervention and thus malleable during the early childhood years. The proposed 5-year longitudinal, multi-method study will build this evidence base by first assessing a pre-k boost to low-income children?s self-regulatory, education, and health outcomes in kindergarten, and then by examining associations among this triad of outcomes, as well as testing whether self-regulatory skills explain associations between pre-k participation and education and health outcomes at kindergarten entry. We then examine mechanisms associated with pre-k classroom self- regulatory features as they explain associations between pre-k participation and kindergarten outcomes, investigating self-regulatory classroom features as mediators of kindergarten self-regulatory, education, and health outcomes. Our final goal capitalizes on the longitudinal study design to explore the processes underlying sustained pre-k impacts: we will test for the presence of and pathways to any sustained pre-k effects through 4th grade, focusing on classroom processes that may underlie fade-out of pre-k impacts. Data will be collected in the Tulsa Public Schools (TPS) district, which hosts a nationally recognized pre-k program, the impacts of which we will study beginning at kindergarten entry. In each year of the proposed project ? from K through 4th grade ? the project will include direct assessments of children?s self-regulatory, education, and health outcomes, classroom observations and teacher interviews to gather information on classroom processes and practices, and parent interviews. To analyze our data, we will employ a mix of econometric, OLS regression, and multilevel modeling approaches. Findings will illuminate the active pathways from pre-k exposure to longer-term education and health outcomes, informing the design of next-generation pre-k programs that acknowledge their role as both early learning and health-promoting interventions.